In a magnetic recording/reproducing apparatus, such as an audio tape recorder or a video tape recorder (VTR), investigations for increasing the density and/or quality of recording signals are presently under way. In keeping up with such tendency towards high-density recording, so-called metal tapes in which powders of metals, such as Fe, Co or Ni, or alloys thereof, are used as magnetic powders for a magnetic recording medium, or so-called deposited tape in which a ferromagnetic metal material is directly deposited on a base film by a vacuum thin film forming technique, have been developed and put to practical application in various technical fields.